What is the minimum size THWN-2 grounded feeder conductor required to supply an individual dwelling unit with a calculated neutral load of 85 amperes?

What is the minimum size THWN-2 grounded feeder conductor required to supply an individual dwelling unit with a calculated neutral load of 85 amperes?

• A. 6 AWG
• B. 2 AWG
• C. 4 AWG
• D. 1 AWG

Answer: (C)

To determine the minimum size for a THWN-2 grounded feeder conductor supplying an individual dwelling unit with a calculated neutral load of 85 amperes, it is essential to refer to the National Electrical Code (NEC) guidelines, specifically Table 310.16. For a dwelling unit, the size of the feeder conductor must be adequately rated to handle the continuous load, which is calculated based on the demand. In this case, a load of 85 amperes is specified. When assessing the required conductor size, you should consider the typical ratings for copper conductors in a residential application. According to the NEC, a 4 AWG THWN-2 copper conductor is capable of handling a continuous load of approximately 85 amperes when considering the temperature rating and installation conditions. This means that a 4 AWG conductor is the minimum size that can safely deliver the stated load without overheating or causing other electrical issues. Thus, the choice of 4 AWG for the feeder conductor matches both the calculated load of 85 amperes and the NEC recommendations for proper safety and performance, making it the correct answer.

To determine the minimum size for a THWN-2 grounded feeder conductor supplying an individual dwelling unit with a calculated neutral load of 85 amperes, it is essential to refer to the National Electrical Code (NEC) guidelines, specifically Table 310.16.

For a dwelling unit, the size of the feeder conductor must be adequately rated to handle the continuous load, which is calculated based on the demand. In this case, a load of 85 amperes is specified.

When assessing the required conductor size, you should consider the typical ratings for copper conductors in a residential application. According to the NEC, a 4 AWG THWN-2 copper conductor is capable of handling a continuous load of approximately 85 amperes when considering the temperature rating and installation conditions. This means that a 4 AWG conductor is the minimum size that can safely deliver the stated load without overheating or causing other electrical issues.

Thus, the choice of 4 AWG for the feeder conductor matches both the calculated load of 85 amperes and the NEC recommendations for proper safety and performance, making it the correct answer.